The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: enjenjo on April 20, 2005, 10:29:30 PM
Any one with experience on how this holds up? I know Eastwood, and harbor freight both have systems, is one better than the other? Clue me in guys
Frank...
I have helped a Buddy of mine. He bought the Harbor Freight model, but we wound up going to the Easterwood powder. It is a whole lot nicer finish that the HF powder. He has parts on a 39 Studebaker truck that have been on 3 years, and still look good. Most of the parts are under the hood, and the brake & gas pedals, so they are not exposed to weather all the time. The HF gun works fine, it's just the powder is not so good. We rigged up an oven out of one of his rent houses. It really worked good..
I've been using the Eastwood cheapy kit for about eight years now. it's holding up way better than I am. For a durable long lasting finish powder coating is the way to go IMHO. I've been playing with mixing the powders to come up with some otherworldly effects. I'll have to get a pic of the jewelery box I made for my oldest grandaughter. My sister thinks I should satrt making them for crafts fairs. The only problems I have with powder coating are the amount of wasted powder and metals with chemical impurities, oil, coolant etc. I've got a few pieces I need to coat today, if anything comes out special I'll post a pic.
Jbird 8)
Anyone got any details on where these are avail from?
Ive been paying out quite a bit on powder coating and still have alot more to do.
Quote from: "Mr Cool"Anyone got any details on where these are avail from?
Ive been paying out quite a bit on powder coating and still have alot more to do.
Chris, Go to www.eastwood.com and on the front page there is a panel with the hotcoating section click on it and you're there. It is a nifty machine and the guys I've talked to that have one say they really like it especially for the small brackets and such, even carbs. Hope this helps. Bill
where did we end up?
HF powder coat system good, powder bad?
Eastwood powder is good ?
I use the eastwood cheep gun and their powder, I started with an old electric oven. It worked but was almost impossible to control the temp. I now have the HF powder coating oven. It works better but it is so small I cant get a lot of my parts in it. I have managed to get the front control arms from my 61 galaxie in the oven but I knocked enough powder off that the look bad in places. I have found that if I only do one side then bake that then do the other side of a part I have better results.
My complaint with the cheapie system it that I can't seem to get the coating thickness uniform, it can be to thin in places and to thick in others and it will sag if it is to heavy.
Scott...
Quote from: "ONE37TUDOR"I use the eastwood cheep gun and their powder, I started with an old electric oven. It worked but was almost impossible to control the temp. I now have the HF powder coating oven. It works better but it is so small I cant get a lot of my parts in it. I have managed to get the front control arms from my 61 galaxie in the oven but I knocked enough powder off that the look bad in places. I have found that if I only do one side then bake that then do the other side of a part I have better results.
My complaint with the cheapie system it that I can't seem to get the coating thickness uniform, it can be to thin in places and to thick in others and it will sag if it is to heavy.
Scott...
Scott,
Try preheating the part to 175 degrees, painting and put back into the oven to cure. The preheating should get the powder to gel upon contact and avoid the thin areas. My powder coater suggested preheating my frame before painting to get a thicker dry film coating.
The key to getting more uniform coating with powder is similar to wet paint. "practice" Also a tip. Powder guns charge the powder with the negative ion of the DC current. The part must be earth grounded for the powder to attract to the part. In area's that are recessed the powder does not want to go in there because of a factor known as the faraday cage effect. You should coat those area's first... like cutting in with a wet gun. after those area's are coated look at whats left and coat them accordingly.
The Faraday effect is like putting two like poles of a magnet together, they repel each other. You have to over come this by moving the gun closer in these area's and forcing it in. The common mistake is to coat the whole peice and then try to get those area's which causes non uniform coating.
Sedanman :)
Thanks for the tips, some of this confirms what I have learned and some I suspected (need more practice) but I would also like to know if the more expensive powdercoating guns have a way to help these situations? Not that I am going to spend the mony to get one but it would give me an excuse for my poor efforts :oops:
pre-heat and cutting in the tight spots. good idears.
thanks.. 8)
I messed around with a friend's Eastwood base model. It is OK for small stuff. Very sensitive to air pressure. And it is not cost effective when you have a lot of stuff to do.
We have an industrial powder coater nearby that also does a lot of race car stuff. For stock colors, which he buys in large quantities, his prices are reasonable. Cheaper than the cost of a comparable amount of powder from Eastwood.
For small stuff I do my own prep work. For larger items, like wheels, I have a professional sand blaster do the prep. I do my own prep because it saves money and I am willing to spend the extra time to get the details right. Also, the powder coater is only set up to use aggressive sand blasting. And I can bead blast or use a finer medium on small parts like alternator cases.
The powder coater has a large oven, it will take complete chassis, and it is expensive to run. So he tries to do large runs of a single color. He may not do my desired color for several weeks. On a day when the powder coater is doing my color I'm waiting at the door when he opens up. We hang the stuff and I go to the cafe for breakfast. The stuff is usually ready when I get back, or shortly thereafter.
Quote from: "ONE37TUDOR"Thanks for the tips, some of this confirms what I have learned and some I suspected (need more practice) but I would also like to know if the more expensive powdercoating guns have a way to help these situations? Not that I am going to spend the mony to get one but it would give me an excuse for my poor efforts :oops:
ONE37TUDOR, I never used one of the cheap units that Harber or Eastwood has. We use an expensive unit built by Ransburg Corp. These units have many adjustments on them. Powder flow in grams per minute, voltage adjustments, defusser air adjust and fuidization air adjust. The guns also have different tips you can change out for specific work. These settings allow the coater to adjust to almost any geometry of part.
Sedanman :D
Thanks again, that is out of my league but where I live there are no powdercoaters that have lasted for more than a few months so I have started to try to do some of the small parts myself. I would definitely take it to the pro if I could.
One thing I have noticed is that parts sandblasted with black beauty appear to cover better and more uniformly that those blasted with #3 or #4 blasting sand? The blasted texture between #3 sand and the black beauty appears to be about the same but the surface with the black beauty covers more easily and uniformly using the same gun techniques?
Scott...
Quote from: "ONE37TUDOR"Thanks again, that is out of my league but where I live there are no powdercoaters that have lasted for more than a few months so I have started to try to do some of the small parts myself. I would definitely take it to the pro if I could.
One thing I have noticed is that parts sandblasted with black beauty appear to cover better and more uniformly that those blasted with #3 or #4 blasting sand? The blasted texture between #3 sand and the black beauty appears to be about the same but the surface with the black beauty covers more easily and uniformly using the same gun techniques?
Scott...
Scott, In the coating industry thats what we call a metal profile. The sand blast of different media's leave a different profile on the surface. Powder is more forgiving and hides the profile better then liquid coating. Powder really likes a smooth phosphated surface, but will work well over a media blasted surface also.
Vic...
I'm interested in this as I would like to coat some of the smaller parts on my lakester. I'm not interested in how good they look, just that they will be more resistant to the salt and easier to clean than maybe a painted piece and also maybe quicker than painting.
So with that in mind is it going to matter which system I buy, HF or Eastwood. I'm thinking the HF gun and the Eastwood powder from what you guys have said.
I'll sand blast the parts with local sand. It is what they call "blow sand" and is real fine and leaves a fine white look to the part.
There is a local guy where I buy my metal that powder coats and seems reasonable, but it always seems things cost more when I pick them up than what we talked about before hand :x . I'm thinking he could nickle and dime me to death.
One last thing. How much clearance in holes do I need? If I have a 1/2 inch bolt in a 1/2 inch hole does the hole now need to be 9/16th. Smaller holes I can go in 64ths, but over 1/2 I'd have to go in 16ths.
c ya, Sum
Up to 3/8" I make the holes 1/32 bigger, over 3/8, I go 1/16 bigger. Of course I do that on all parts anyway. It makes assembly much more pleasant.
I agree with Frank about the hole sizes. Powder goes on much thicker then liquid and makes the holes smaller. We never have that luxury from our customers and always plug all blind holes, threaded holes and open holes to hold down complaints. There are different powders for specific applications and uses other then appearance. Epoxy powders have great chemical and salt resistance but chalk or dull out in UV light (sunlight). Polyesters and urethanes are best for parts that will see the sunlight but does not have the chemical resistance of epoxy. The best of both worlds are the hybrids. They are combination of both. Please remember that the thermal cure of powder is the most important factor. Unlike air dry paint, if it is not fully cured it will never cure on its own. It will chip and peel and you will not be happy. I have seen this situation give powder a bad name because the user did not understand how to check for full cure. Hope this helps. :)
THANK YOU for sharing your expertise! .....Of course, that leads to more questions.
Quote from: "sedanman"Epoxy powders have great chemical and salt resistance but chalk or dull out in UV light (sunlight). Polyesters and urethanes are best for parts that will see the sunlight but does not have the chemical resistance of epoxy. The best of both worlds are the hybrids. They are combination of both.
Does the exposure of the epoxy to UV light cause it to degrade, or is it simply an appearance issue?
Quote from: "sedanman"Please remember that the thermal cure of powder is the most important factor. Unlike air dry paint, if it is not fully cured it will never cure on its own. It will chip and peel and you will not be happy. I have seen this situation give powder a bad name because the user did not understand how to check for full cure.
Will you please elaborate on the cure process and how to check for full cure?
Is the cure process the same for the various types of powders?
Two more questions, and then I'll duck:
Does the silica deposited on the metal from sandblasting or glassbeading inhibit the powder from adhering well? ....Should the parts be washed with solvent to remove the silica before powder application?
Thank you for your patience! :oops:
Thats fine, finaly you guys have started a subject I can help with. I have been in the coating Industry for 31 years. Now for some answers:
Powder cures by time and temperature. Most powder will come with a tech data sheet that will spell out the temp and time for you. What some don't understand is PMT. this means Peak metal temperature. NOT oven temperature.
Example: If the powder call fr 375 F for 10 minutes most think that they can heat the oven up to 375, put the part in for 10 minutes and it will cure. This will not work in most cases. PMT means the mass of metal must reach 375 F and then be held at that temp for 10 minutes. The thicker the part the longer it will take to acheive this. Powder has built in cross linker that requires this time and temp to kick over.
You can buy a small hand held digital thermometer with a remote probe fairly cheap. Attach the probe to the part that you want to cure and do a test run with out powder on it. Time how long it takes to reach PMT.
Now you are ready to powder coat the peice and bake. Remember that if you put more then one part in the oven that will change the time required to hit PMT. If they are real small parts this may not matter, such as door handles. If we are talking A frames or Brake drums, it will matter.
Checking for cure: After the parts have completely cooled off you will need a Q-tip and some Acetone. Wet the Q-tip with acetone and rub the part in a no show area 25 double rubs. You should not see any more tha en a slight spot on the Q-tip and the powder should not soften. If it does it is not cured.
As for the sand blast. I powder coated every Desiel engine in all Ford trucks from 1996 to 2003, and they were all sand blasted prior to coating.
I would just make sure that any loose sand has been removed by air blast.
DO NOT touch the fresh blasted surface with your bare hands. It will absorb the natural oil from you hands and the powder will fail there first.
Hope this helped
Sedanman
Quote from: "sedanman"Checking for cure: After the parts have completely cooled off you will need a Q-tip and some Acetone. Wet the Q-tip with acetone and rub the part in a no show area 25 double rubs. You should not see any more tha en a slight spot on the Q-tip and the powder should not soften. If it does it is not cured.
One more question.......
If it turns out the powder has not cured can you put it back in the oven or do you have to strip it and start over?
Thanks
MM64 8)
Great info. Thanks :D .
For the small parts that I want to coat on the lakester it isn't like they are going to be in salt water. It is just that salt gets on things there and I need to clean the car good when I get home. I've had others there tell me the salt will come off the powder coated pieces easier.
So will just the regular powders work for what I'm trying to do?
Also I don't want to coat any pieces that I think will need changes to as I feel it would be easier for me to grind paint down and weld and/or cut whatever needs changing. So the frame and other major parts I don't want to coat as I'm sure there will be changes to the car as I go along.
(http://purplesagetradingpost.com/sumner/bvillecar/r-springshock-32.jpg)
Parts like these are what I'm talking about. What about the bushings I have in some of those parts? Can they be pluged and/or taped?
Thanks again,
Sum
Quote from: "MrMopar64"Quote from: "sedanman"Checking for cure: After the parts have completely cooled off you will need a Q-tip and some Acetone. Wet the Q-tip with acetone and rub the part in a no show area 25 double rubs. You should not see any more tha en a slight spot on the Q-tip and the powder should not soften. If it does it is not cured.
One more question.......
If it turns out the powder has not cured can you put it back in the oven or do you have to strip it and start over?
Thanks
MM64 8)
Yes... It can be rebaked. As a matter fact most powder can withstand and over bake of twice the recomended time at PMT. If recoating though the powder should be sanded first to knock off the gloss and provide a profile for the second coat to adhere to. Use at least 220 grit.
Vic.... :)
Quote from: "1FATGMC"Great info. Thanks :D .
For the small parts that I want to coat on the lakester it isn't like they are going to be in salt water. It is just that salt gets on things there and I need to clean the car good when I get home. I've had others there tell me the salt will come off the powder coated pieces easier.
So will just the regular powders work for what I'm trying to do?
Also I don't want to coat any pieces that I think will need changes to as I feel it would be easier for me to grind paint down and weld and/or cut whatever needs changing. So the frame and other major parts I don't want to coat as I'm sure there will be changes to the car as I go along.
(http://purplesagetradingpost.com/sumner/bvillecar/r-springshock-32.jpg)
Parts like these are what I'm talking about. What about the bushings I have in some of those parts? Can they be pluged and/or taped?
Thanks again,
Sum
I would use epoxy on the parts you have shown. Go to your local hardware and try to locate some rubber stoppers to plug all those holes with. I would disassemble the second peice down and coat it in peices. I think I see threaded rod in a couple of those peices. Don't powder coat those if you want them to ever function again. Use zinc or nickle plated rod. I would remove the bushings if you can, if not plug them. Laboratory stoppers for test tubes come in many sizes and are heat resistant and can be cleaned off and used over and over. If you can't find those cork can be used, but they are a one time use and will fall apart upon removal.
Lab supply houses carry the stoppers. You are correct about not coating peices that will require further fabrication. Powder is harder to grind off and is plastic, so it melts when you try to weld close to it.
Vic... :)
I bought a kit and some powders from Caswell Plating, out of New York, but have not used them yet. Has anyone had experience with the Caswell powders? Here's a link if anyone's interested. If memory serves me, the powder prices are much better than Eastwoods. Thanks.
http://www.caswellplating.com/
Quote from: "nocentsracing"I bought a kit and some powders from Caswell Plating, out of New York, but have not used them yet. Has anyone had experience with the Caswell powders? Here's a link if anyone's interested. If memory serves me, the powder prices are much better than Eastwoods. Thanks.
http://www.caswellplating.com/
I checked out the kit.The only thing I question is the 17KV. We charge our powder 70 to 100kv. But we are high production facility and we are dependant upon first pass transfer efficiency.
Vic... :)